Reality! Wait! Since the TwinAir is driven by a twocylinder motor, similar to the first 500 back 1957 such greenness is attained.

A twin! In a 500! To be exact, it's an in-line two, displacing 875cc and creating, inside the turbo-charged kind seen here, 84bhp - a naturally-aspirated 64bhp and hotter 104bhp turbo variant will follow. With Fiat's MultiAir time and stopstart technology, the twin 500 will return a maintained 69.9mpg and emit only 95g/kilometer of CO2: cleaner when compared to a Polo BlueMotion, cleaner when compared to a Honda Insight.

Enough numbers. You need to understand the way that it sounds.

The TwinAir is, for this type of dinky engine, smooth and astonishingly refined. Should you've had the misfortune to push the threecylinder Corsa in the midNineties, you'll understand how binary few-cylindered engines may be. The TwinAir, picking up readily from low revs, however, is completely linear in its answers and providing a fine spread of electricity.

We had visions of the whipcrack motorcycle motor, fizzing up-to high revs with feather-light flywheel result, however the TwinAir is not anything like this. Fiat's engineers have certainly worked hard to banish the Double's twocylinder character towards comfortable, easy-drivin' etiquette.

Costs are likely to begin around?1,500 more compared to the entrylevel 1.2litre four-bud petrol - its driveability and amazing market can ensure it is the Cinq of selection. Which motor represents merely the beginning of Fiat's twocylinder strategies: a gas-electric hybrid model should enter production within another couple of years.

For now, the people at Fiat ought to be applauded for a bit of engineering. The TwinAir provides a dazzling prospect within an age when smalldisplacement engines are becoming virtual clones of one another.